I'd happily take the other side of that bet although I acknowledge it's not a slam dunk in terms of whether or not the NFL will play.
The NFL doesn't need fans in the stadiums to play the games. TV money dwarfs money brought in at the gate. I'm an Eagles season ticket holder. They've already asked me if I want to defer my tickets til next year so no fans are being forced to buy tickets this year. They've also telegraphed that they expect limited # of fans allowed in, if at all.
All you really need besides players are the coaching staffs, refs and a handful of sideline personnel. Ample precautions can be taken with all three to protect them. There is plenty of room on the sidelines to spread everybody out.
As for the players, for every one player that would opt out there are 100 that would be bummed if no season. These guys have very limited careers and want to make money while they can. As Steve Holt said, the statistical risks for very healthy guys in their the 20s and low 30s with no pre-existing conditions are extremely low. I agree with him that they take more health risks playing this violent game than the risk to them from covid and that's not to minimize the impact of covid overall.